Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
Gum Disease Activates HIV, Study Says
Gum disease produces an acid that may push HIV-infected people to develop full-blown AIDS, a Japanese study says.
Butyric acid hinders an enzyme called HDAC that prevents the proliferation of HIV, Kuniyasu Ochiai, chair of the microbiology department at Nihon University in Tokyo, told Agence France Presse.
"Serious periodontal disease could lead to the development (of AIDS) among HIV-positive people ... although the probability largely depends on individual physical strength," Ochiai said.
Previous studies have linked gum disease to heart disease and diabetes, but this is the first to find that gum disease activates HIV, Ochiai told AFP.
The study is scheduled to appear in the March issue of the Journal of Immunology.
Exercise May Reduce Colon Cancer Risk
Exercise can reduce the risk of colon cancer, according to U.S. researchers who reviewed 52 studies and concluded that the most active people are 24 percent less likely than the least active to develop the disease.
The studies included in the review included many different types of physical activity, ranging from going to the gym and running to doing manual labor, BBC News reported.
The findings were published in the British Journal of Cancer.
"These results give us a very reliable calculation of the positive effect that exercise can have on reducing colon cancer risk," said lead researcher Dr. Kathleen Wolin, of Washington University School of Medicine in St. Louis, BBC News reported.
"It's very positive to see that exercise has such a clear benefit in reducing cancer risk and we hope it will encourage people to enjoy a healthy, active lifestyle as well as treating it as a way to minimize their colon cancer risk," Wolin added.
Peanut Plant Owner Had Tainted Products Shipped: Report
The owner of Peanut Corp. of America, the company suspected of causing the nationwide salmonella outbreak, told his employees to ship products tainted with the bacteria even after receiving test results identifying the presence of salmonella, according to company e-mails disclosed Wednesday by U.S. lawmakers, the Associated Press reported.
The e-mails, obtained by a House of Representatives' panel investigating the outbreak, revealed that company owner Stewart Parnell ordered the tainted products to be shipped anyway because he was worried about lost sales, the news service reported.
Parnell was subpoenaed to appear before Congress on Wednesday for questioning on the salmonella outbreak that has sickened more than 600 people, been linked to eight deaths, and prompted one of the largest recalls in U.S. history -- more than 1,800 products. His plant in Blakely, Ga., is blamed for the outbreak, the AP reported.
Parnell showed up for the Congressional hearinng, but refused to answer questions, invoking his constitutional right not to incriminate himself, the AP said.
Rep. Greg Walden, R-Ore., revealed the company e-mails during a House Energy and Commerce hearing.